Conventionally, there is known a motor drive apparatus including an inverter that drive a motor generator, a boost converter that boosts a voltage from a battery and supplies the inverter with the post-boost voltage, and a controller that provides the boost converter with a target boost voltage corresponding to a target operation state of the motor generator (for example, refer to Patent Document 1). The apparatus is provided with a map that previously defines a relationship between a torque command to the motor generator, a rotational speed of the motor generator, and the target boost voltage of the boost converter. The controller controls the boost converter so as to boost the voltage from the battery up to the target boost voltage derived from the map to correspond to the torque command and the rotational speed when the voltage from the battery is to be boosted.    [Patent Document 1] Japanese Patent Laid-Open No. 2007-202311